Assuming Megalo Cannon is last, there are some pokemon that have been missed this generation. Here are a few psychics (mostly from gen 1).
Abra 60 HP sychic:
sychic: Psyshock 10
Flip a coin, if heads, the defending pokemon is now paralyzed.
Weakness: sychic: 2x
Resistance:
Retreat Cost: :colorless:
Kadabra 80 HP sychic:
:colorless: Recover
Discard an energy attached to this pokemon and remove all damage from this pokemon.
sychic::colorless::colorless: Super Psy 60
Weakness: sychic: 2x
Resistance:
Retreat Cost: :colorless::colorless:
Alakazam 130 HP sychic:
Ability: Psy Exchange
Once during your turn, before your attack, you may shuffle your hand into your deck and draw a number of cards equal to the number of cards shuffled in.
sychic::colorless: Psychic Teamup 30x
This attack does 30 damage for each sychic: pokemon you have in play.
Weakness: sychic: 2x
Resistance:
Weakness: :colorless::colorless::colorless:
Gastly sychic: 50 HP
Ability: Transparency
When your opponent attacks this pokemon, flip a coin, if heads, prevent all effects of that attack on this pokemon.
sychic: Curse Drop
Place 1 damage counter on your opponents pokemon in any way you like.
Weakness:
Resistance:
Retreat:
Haunter sychic: 70 HP
Ability: Transparency
When your opponent attacks this pokemon, flip a coin, if heads, prevent all effects of that attack on this pokemon.
sychic: Curse Drop
Place 3 damage counters on your opponents pokemon in any way you like.
Weakness:
Resistance:
Retreat:
Gengar sychic: 120 HP
Ability: Transparency
When your opponent attacks this pokemon, flip a coin, if heads, prevent all effects of that attack on this pokemon.
sychic: Curse Drop
Place 6 damage counters on your opponents pokemon in any way you like.
Weakness:
Resistance:
Retreat:
And I'll likely be updating this.
Abra 60 HP sychic:
sychic: Psyshock 10
Flip a coin, if heads, the defending pokemon is now paralyzed.
Weakness: sychic: 2x
Resistance:
Retreat Cost: :colorless:
Kadabra 80 HP sychic:
:colorless: Recover
Discard an energy attached to this pokemon and remove all damage from this pokemon.
sychic::colorless::colorless: Super Psy 60
Weakness: sychic: 2x
Resistance:
Retreat Cost: :colorless::colorless:
Alakazam 130 HP sychic:
Ability: Psy Exchange
Once during your turn, before your attack, you may shuffle your hand into your deck and draw a number of cards equal to the number of cards shuffled in.
sychic::colorless: Psychic Teamup 30x
This attack does 30 damage for each sychic: pokemon you have in play.
Weakness: sychic: 2x
Resistance:
Weakness: :colorless::colorless::colorless:
Gastly sychic: 50 HP
Ability: Transparency
When your opponent attacks this pokemon, flip a coin, if heads, prevent all effects of that attack on this pokemon.
sychic: Curse Drop
Place 1 damage counter on your opponents pokemon in any way you like.
Weakness:
Resistance:
Retreat:
Haunter sychic: 70 HP
Ability: Transparency
When your opponent attacks this pokemon, flip a coin, if heads, prevent all effects of that attack on this pokemon.
sychic: Curse Drop
Place 3 damage counters on your opponents pokemon in any way you like.
Weakness:
Resistance:
Retreat:
Gengar sychic: 120 HP
Ability: Transparency
When your opponent attacks this pokemon, flip a coin, if heads, prevent all effects of that attack on this pokemon.
sychic: Curse Drop
Place 6 damage counters on your opponents pokemon in any way you like.
Weakness:
Resistance:
Retreat:
And I'll likely be updating this.